diff -r 000000000000 -r 6474c204b198 toolkit/devtools/server/tests/unit/test_attach.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/toolkit/devtools/server/tests/unit/test_attach.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,37 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+var gClient;
+var gDebuggee;
+
+function run_test()
+{
+  initTestDebuggerServer();
+  gDebuggee = testGlobal("test-1");
+  DebuggerServer.addTestGlobal(gDebuggee);
+
+  let transport = DebuggerServer.connectPipe();
+  gClient = new DebuggerClient(transport);
+  gClient.connect(function(aType, aTraits) {
+    attachTestTab(gClient, "test-1", function(aReply, aTabClient) {
+      test_attach(aTabClient);
+    });
+  });
+  do_test_pending();
+}
+
+function test_attach(aTabClient)
+{
+  aTabClient.attachThread({}, function(aResponse, aThreadClient) {
+    do_check_eq(aThreadClient.state, "paused");
+    aThreadClient.resume(cleanup);
+  });
+}
+
+function cleanup()
+{
+  gClient.addListener("closed", function(aEvent) {
+    do_test_finished();
+  });
+  gClient.close();
+}